Bed, not overturned, left behind court - that's soft (6,4)

I believe the answer is:

cotton wool

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'behind court that's soft' is the definition.
I can't judge whether this defines the answer.

'bed not overturned left' is the wordplay.
'bed' becomes 'cot' (cot is a type of bed).
'overturned' says the letters should be written backwards.
'left' becomes 'wool' (I can't justify this - if you can you should give a lot more credence to this answer).
'not' reversed gives 'ton'.
'cot'+'ton'+'wool'='COTTON-WOOL'

Can you help me to learn more?

(Other definitions for cotton wool that I've seen before include "protective wrapping?" , "Absorbent padding" , "Light, fluffy stuff from plant" , "Natural fibre" , "Fluffy wadding" .)

I've seen this clue in The Daily Express.

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